Psychiatry Research Neuroimaging
August 1, 2026
Kengo Yonezawa, Shinichiro Nakajima, Shuhei Shibukawa et al.
Ketamine may alleviate treatment-resistant depression (TRD) primarily through glutamatergic modulation, with downstream dopaminergic activation. Iron plays an important role in monoaminergic metabolism, that is also implicated in the pathophysiology of TRD. Both Quantitative Susceptibility Mapping (QSM) and Effective Transverse Relaxation Rate (R2*) mapping can determine the extent of iron...
Journal of Affective Disorders
August 15, 2025
Yohei Ohtani, Hideaki Tani, Shiori Honda et al.
3 citations
Approximately 30 % of patients with treatment-resistant depression (TRD) respond to ketamine; however, no replicable predictors of response have been reported. The imbalance between excitatory and inhibitory neurotransmissions may be implicated in the mechanism of action of ketamine. This study aimed to evaluate whether the ratio of glutamate and glutamine (Glx) to GABA levels at baseline in...
The International Journal of Neuropsychopharmacology
August 1, 2025
Yuko Ohtani, Hiroe Tani, Shiori Honda et al.
Abstract Background Only 18-45% of individuals with treatment-resistant depression (TRD) respond to intravenous ketamine therapy. Although some neurobiological predictors of response to ketamine have been reported, none have been consistently replicated across multiple studies. The imbalance between glutamatergic excitatory and GABAergic inhibitory neurotransmissions is implicated in the...
The International Journal of Neuropsychopharmacology
February 1, 2025
Kengo Yonezawa, Hideaki Tani, Shuhei Shibukawa et al.
Abstract Background Whereas ketamine has displayed robust antidepressant effects in treatment-resistant depression (TRD) (Han et al., 2016), only 30-40% of patients with TRD respond to ketamine therapy (Wilkinson et al., 2018; Sakurai et al., 2020). Several postmortem studies have shown decreased myelination in patients with depression (Hamidi, Drevets and Price, 2004; Altshuler et al., 2010),...
Schizophrenia research. Cognition
May 16, 2016
Syudo Yamasaki, Shuntaro Ando, Shinsuke Koike et al.
Peer victimization increases the risk of experiencing psychotic symptoms among clinical and general populations, but the mechanism underlying this association remains unclear. Dissociation, which is related to peer victimization and hallucinatory experiences, has been demonstrated as a significant mediator in the relation between childhood victimization and hallucinatory experience among adult...